Between the years of 1990 and 2015, Cambodia saw the region’s highest rate of improvement in the UN’s Human Development Index, a metric that tracks wellbeing, though the country’s overall score remains well below the average for countries in East Asia and the Pacific, a new report from the UN Development Programme shows.

The Kingdom has seen improvements in health, education and overall living standards since the index was first measured, the report says, though the country’s overall HDI ranking in 2015 was still 143 out of 188 countries. That spot placed Cambodia among the medium development group, along with fellow ASEAN states Laos (138) and Myanmar (145).

In the 25 years studied, Cambodia’s HDI value – a composite figure meant to represent measures such as life expectancy, education and incomes – increased by 57 percent, to 0.563. On average, however, it still lags behind the medium development group’s average HDI of 0.631, and the regional average of 0.721.

“It’s a proxy that the lives of ordinary Cambodians have improved,” Napoleon Navarro, a senior policy adviser at UNDP, said of the index’s findings. “Cambodia has a lot to be proud of, but if it wants to sustain this, it needs to consider investing in human capital and to prepare for climate change.”

In the two decades since 1995, Cambodia’s gross national income increased nearly 280 percent, life expectancy at birth increased by more than 15 years and the average years of schooling attained also doubled.

Despite this, Navarro said the slowest improvements overall have been in the education sector. While the state has increased investment in education, “ordinary Cambodians are not investing as much as the government”, he said.

“Cambodians are dropping out [of school] to work,” he said, which can seem good in the short term because it generates income, but in the long run, limits their possibilities.

Access to a diverse range of jobs is also still an issue, said Federico Barreras, a project manager at the Open Institute. “I think Cambodia would benefit from having more diversified sectors,” he said. “It would be more attractive for investors as well.”

When it comes to the gains the country has made in health, Chum Sopha, executive director of the NGO Health and Development Alliance, said the sector has seen improvement in human resources, but less so in services.

“In terms of services, they still remain unsatisfactory,” he said. Despite improvements, Cambodia still faces challenges such as reducing poverty and inequality to ensure that certain populations are not left behind.

For example, indigenous people are disadvantaged by higher-than-average poverty rates, limited access to education and health, and fewer representatives than majority groups in decision-making institutions.

“The same groups are doubly deprived because their livelihoods rely more heavily on natural resources and agriculture than those of other population groups, and the impact of climate change on their livelihoods has been high,” the report reads.